The battle against Brock is a CMOA in terms of teamwork for Red's team; Nidoran dealing out most of the damage, Spearow and Rattata distracting Onix to get it to waste some PP, and Metapod slowing Onix down with String Shot and thus allowing Charmander to deliver the final blow to win the match.
Most of the battles qualify, really. Its very faithful to the games while showing it off in an anime style, along with remix version of the game's BGM.
Battle at the Pokemon Tower. Koffing has the upper hand and Charmeleon's can't see through the smog when Cubone clears the smoke with Bonemerang! We've got a Double Battle here, folks!
Seeing Giovanni kick Red's ass during the Silph Co. battle and the resulting explosion and collateral damage. To elaborate, his Nidoqueen curbstomps Charizard in just a few hits, and Charizard can't even land a single hit!
His Gym Battle was just as awesome. Rhyhorn, who should be at a severe disadvantage, pretty much hands most of Red's teams' asses on its own. Red really had to earn that victory.
The Seismic Toss against Rhydon.
And Rhyhorn taking down Jolteon with a Thunderbolt. Especially because Giovanni pulled that off just to show he could and to mock him!
Red defeating Blue and winning against the Pokémon League. Special mention also goes out to Blue, who manages to beat the Elite Four first before Red.
Special mention to the sheer power behind the Fire Blast Charizard launches against Blastoise, which proves to be the finishing blow. And this is after Blastoise hit Charizard with Hydro Pump, which it withstood against all odds.
The last Episode: The Reveal of Mega Charizard X and the subsequent battle against Mewtwo. "Awesome" isn't even enough to describe it.
And even then, Mewtwo still gives a good fight against Mega Charizard X. It's even better if you remember that Mewtwo has already wasted Red's team, including Gengar and Articuno.
Dat snarl! This version really lives up to its reputation for being vicious.
Mewtwo knocks Charizard out of mid-air with an attack, and Red proceeds to dive under him to catch him.
The finishing blow in and of itself.
Red: Charizard! ONE LAST MEGA PUNCH!
Mega Charizard X: *Socks Mewtwoso hard that he flings him across the cave.*
This is followed by Red catching Mewtwo in only two Ultra Balls.IT'S NEVER THAT EASY IN THE GAMES. NEVER. But of course, in the original games, you aren't given a Mega Charizard X.
For many fans, this doubled as a real-life CMOA as well. After Game Freak had all of us believe that Mega Charizard (Y)'s reveal was the final nail in the coffin for Charizard gaining the Dragon type, Mega Charizard X shows up out of nowhere, wielding the Dragon type and ready to kick ass both in Origins and in the games.